Greenhouse effects speech essay

Warmer air in the atmosphere holds lots of moisture than the cool air which results in the flood in many areas. Both droughts and floods adversely affect the crop production. These are natural disasters affecting human, animals and plants lives in many aspects. Coral reefs are considered to be the most important for the water lives as they provide food and shelter to the fish, crabs, sea turtles, and other aquatic animals. So, the global warming is a big threat to the existence of life here on the earth in future. It needs to be solved by the global effort of people on urgent basis to maintain healthy and happy life here.

As with all gases, the density of SF
6 affects the resonance frequencies of the vocal tract, thus changing drastically the vocal sound qualities, or timbre, of those who inhale it. It does not affect the vibrations of the vocal folds. The density of sulfur hexafluoride is relatively high at room temperature and pressure due to the gas's large molar mass . Unlike helium , which has a molar mass of about 4 grams/mol and gives the voice a childish and a " chipmunk like" quality, SF
6 has a molar mass of about 146 g/mol, and the speed of sound through the gas is about 134 m/s at room temperature, giving the voice a "demonic" quality when SF
6 is inhaled. [31] [32] For comparison, the molar mass of air, which is about 80% nitrogen and 20% oxygen, is approximately 30 g/mol which leads to a speed of sound of 343 m/s. Inhalation of SF
6 causes a lowering of the timbre , or frequency of the formants, of the vocal tract, by contrast with inhalation of helium, which raises it. [33]